Authorities in Beijing said Wednesday they plan to get rid of 1,200 high-polluting enterprises by 2015 to improve air quality in the Chinese capital, one of the world's most polluted cities.

The move follows a public backlash over the heavy smog that often envelops Beijing -- sometimes so thick that it delays planes and trains going to and from the city -- sparking health concerns among the general population.

The Beijing Municipal Environmental Protection Bureau said in a statement it planned to eliminate 1,200 high-polluting facilities such as foundries, chemical plants and furniture factories by 2015.

"Industrial pollution is one of the main factors influencing the air quality in this city," the bureau said. It did not specify whether the enterprises would be shut down or relocated to other areas of the country.

Air quality in the capital has been bad for years, but netizens focused on it late last year after the US embassy started publishing its own pollution readings, which are often alarming.

The embassy measures PM2.5 -- the smallest, most dangerous pollution particles in the air -- and posts the results on a Twitter feed. They often rank as "very unhealthy" or "hazardous".

Beijing's government eventually caved into online pressure and said it would start publishing its own measures of PM2.5, as opposed to basing information on particles of 10 micrometres or larger, known as PM10, which are less harmful.

It has also set up bicycle rental kiosks in the city in a bid to ease traffic congestion -- another source of pollution. Authorities are also mulling new bike lanes.